The power switches used in power converters are typically submitted to substantial voltages. By way of example, the power switches of power converters used in applications which require a conversion of a mains voltage (at e.g. 230V) to a different output voltage may be submitted to peak voltages which are at a multiple of the mains voltage.
The submission to high voltages may cause avalanche effects within the power switches, which may eventually lead to a malfunction of the power switches and the power converters. In order to avoid such avalanche effects (also referred to as break down effects), power switches are typically over-dimensioned, such that the power switches are not operated at their respective operational limits. In particular, power switches having an increased break-down voltage are being used. However, the over-dimensioning of the power switches typically leads to increased costs, and it is therefore desirable to provide means which allow the selection of power switches that are operated near to their operational limits.
Alternatively or in addition, protection circuits (e.g. snubber circuits including a snubber capacitor) may be used to protect the power switch of a power converter. Such protection circuits may comprise energy absorbing circuits used to eliminate voltage spikes caused by inductances when the power switch of a power converter opens. Such protection circuits typically lead to additional losses of the power converters which are undesirable. Furthermore, the components of such protection circuits may need to be over-dimensioned in order to ensure safe operation of the power switches. The over-dimensioning of the protection circuits typically adds to the costs of the power converter.
In view of the above, it is desirable to provide a system and a method which allow the selection of power switches and/or associated protection circuits that have a reduced operational margin, in order to reduce the costs and/or the power losses of power converters comprising such power switches and/or protection circuits.